| γ - Linolenic acid has attracted great interest and got extensive application due to its distinctive physiological functions. The supply of its natural resource has failed to meet demond. People is making attempts to produce γ - linolenic acid using microorganisms, because of the unique advantages of microoganisms, such as high growth rate and simple culture condition. Microoganisms are a new enormously potential resource of γ-linolenic acid. This dissertation investigates breeding of strain for producing y - linolenic acid, fermentation conditions, effective method for extracting lipid containing γ - linolenic acid, preparation of the lipid inclusion complex and physiological activities of the lipid, with Mortierella as experiment material.According to the breeding thought, through once mutagenesis two strains producing γ - linolenic acid are screened, γ - Linolenic acid content and yield increase by over 40% than that of their start strain.The activity of the microsomal membrane-bound malic enzyme was discovered to be significantly positively related with y - linolenic acid content of the mycelial lipid of Mortierella, and the role of the enzyme was demonstrated to supply NADPH for fatty acid desaturation.The effect of various culture time and two temperature stages on y-linoienic acid content and yield of mycelial lipid was investigated, with the discovery: (1) In the basic medium, fermenting 96hr at 30℃, the dry cell weight, lipid yield, y -linolenic acid content and yield, all reach their climax. This moment, the fermentation must be stopped, or else, all above-mentioned targets will decrease. (2) The mycelial rapidly grow before culturing 72 hours. The fungal cells start to rapidly synthesize y - linolenic acid after culturing about 72 hours at 30°C, which forms the basis for correctly selecting the time to change...
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